The subject matter disclosed herein relates generally to additive manufacturing systems and, more particularly, to methods and systems for real-time enhancement of the build parameters of additive manufactured components.
At least some additive manufacturing systems involve the buildup of a powdered material to make a component. This method can produce complex components from expensive materials at a reduced cost and with improved manufacturing efficiency. At least some known additive manufacturing systems, such as Direct Metal Laser Melting (DMLM) systems, fabricate components using a laser device and a powder material, such as, without limitation, a powdered metal. While DMLM is used herein, this term is also sometimes referred to as Direct Metal Laser Sintering (DMLS) and Selective Laser Sintering (SLS). In some known DMLM systems, component quality may be impacted by excess heat and/or variation in heat being transferred to the metal powder by the laser device within the melt pool.
In some known DMLM systems, component surface quality, particularly overhang or downward facing surfaces, is reduced due to the variation in conductive heat transfer between the powdered metal and the surrounding solid material of the component. As a result, local overheating may occur, particularly at the overhang surfaces. The melt pool produced by the laser device may become too large resulting in the melted metal spreading into the surrounding powdered metal as well as the melt pool penetrating deeper into the powder bed, pulling in additional powder into the melt pool. The increased melt pool size and depth, and the flow of molten metal may generally result in a poor surface finish of the overhang or downward facing surface.
In addition, in some known DMLM systems, the component's dimensional accuracy and small feature resolution may be reduced due to melt pool variations because of the variability of thermal conductivity of the subsurface structures and metallic powder. As the melt pool size varies, the accuracy of printed structures may vary, especially at the edges of features.
Both of these challenges are geometry dependent. As a result, an adaptive build parameter needs to be used for every build vector to maintain control over the melt pool size. By enhancing the build parameters of the component in real-time, the quality of the surface finish throughout the printed component as well as the shape accuracy of the part may be improved. In addition, small feature resolution, often lost because of varying thermal conductivity, may also be enhanced.